Many people were shocked with the reveal of the Klassic Characters Tanya and Tremor, but, to the disappointment of many fans, they were announced as paid DLC. Two new fighters were also announced, crossing over the worlds of Friday the 13th, Predator, and Mortal Kombat with the playable fighters Jason Voorhees and Predator. It was also assumed that you will only have access to these characters if you pay for the DLC, but series creator Ed Boon recently tweeted that you will be able to experience these characters for absolutely free through the Premier towers.
The Premiere towers may feature some of these DLC fighters, giving you a chance to give them a try before fully committing to buying them. Boon officially announced this feature yesterday on Twitter, saying, "MKX Sneak Peek: You can complete Premiere towers that feature (and let U play) DLC characters even if you haven’t purchased that character!" He followed that up by tweeting again, saying that if there is a Jason tower, you will be able to compete in it even if you don't own the character.
In the Premiere towers you will be able to play as and against the DLC characters, but details about this mode are still rather unknown. Hopefully more details will be revealed before the game releases next week.